Dr. Sebastian Feld

Assigned Theses

• A method for comparing noisy point-clouds in the context of unforgeable labels
• Optimization of constrained problems using a quantum-assisted genetic algorithm

Completed Theses

• Using Quantum Annealing in Spiking Neural Network Execution
• Reverse Annealing for 3SAT Problems
• Search Space Efficient Community Detection Using Quantum Annealing
• A predictive collision management algorithm for time and risk dependent path planning
• Calculation of Alternative Routes to the Shortest Route Using a Quantum Annealer
• Quantum-Assisted Community Detection
• Supervised Learning of a Homotopy Relation for 2D Trajectories
• Calculating Currency Arbitrage Strategies Using Quantum Annealing
• A Surface-Independent Computation of the Hilbert Curve Using Quantum Annealing, SAT Solver and Evolutionary Algorithm
• Quantum Annealing for Strategic Portfolio Optimization
• Optimization of Aircraft Loading Using Quantum Annealing
• Optimization of Metro Line Arrangements in Network Diagrams Using Quantum Annealing
• Competitive Spatio-Temporal Search with Mobile Agents
• Quantum Annealing in the Calculation of Consumption-Optimized Trajectories in Aircraft Climb
• Smoothing Trajectories Using Quantum Annealing
• Using Quantum Annealing to Solve NP-Hard Variants of the Stable Marriage Problem
• Archetypal Analysis as QUBO Formulation
• Portfolio Optimization Using Quantum Annealing
• Reachability Analysis for a Hypothetical Car Sharing Service
• Gerrymandering as a Combinatorial Optimization Problem
• A Surface-Independent Computation of the Hilbert Curve on a Quantum Annealer
• The Dynamic Time Warping Distance Measure as QUBO Formulation
• Total Runtime Scaling of Quantum Annealing
• Generating, Solving and Rating Sudokus using Quantum Annealing
• Methods for Privacy-Preserving Collection of Usage Data
• Analyses on the Airport Gate Assignment Problem Using Quantum Computing
• Construction of Alternative Routes Using Pathlet Learning
• Online Detection of Structures in Buildings Using Mobile Depth Sensors
• Identification of Unexpected Structural Changes Along Paths Inside Buildings
• Machine Learning with QBoost Using Quantum Annealing Hardware
• Analyzing the Return Value Distribution During Quantum Annealing
• Interactive Web Application for the Archetypal Analysis of Multidimensional Data Sets
• Isochrones for Calculating Complex Routes in Buildings
• Dynamic Navigation Graphs in Changing 3D Environments
• Neural Gas for Dynamic Path Planning
• A Hybrid Solution Method for the Capacitated Vehicle Routing Problem on a Quantum Annealer
• Feedback System Based on DevOps Data for Continuous Quality Assurance of IoT Applications
• Isovist Based Clustering of Trajectories Using Neural Networks
• Mobile Route Planning in Buildings With Moving Targets
• Network Function Virtualization – a Taxonomy
• Concept and Implementation of a Workflow Monitoring Tool for Big Data Processes
• Route Synthesis in Street Networks Based on Freehand Drawings
• Candidate Sets For Alternative Routes in Constrained Free Space Scenarios
• Using Isochrones for Finding Alternative Routes in Indoor Scenarios
• Data Analysis of Probe Request Records for the Determination of Archetypes
• Template-Based Assessment of Self-Weight Exercises Using Sensor Readings
• Detection of Room Entrances in Indoor Navigation Scenarios Based on Isovists
• Trajectory Comparison Without Alignment
• Automatic Detection of Intersections in Buildings Using Isovists
• Scalability of IT Security Using the Example of a Global Financial Services Provider
• Navigation in Buildings
• Cross-Device User Identification
• Segmentation of Paths in Buildings to Analyze the Similarity Behavior
• Context-Sensitive Routing for an Information-Centric Hybrid Radio Network
• Analysis of the Influence of Feature Combinations on the Creation of Archetypal Routes
• Comparison and Analysis of Human and Algorithmic Route Selection in Buildings
• Map-Based Properties of Archetypal Routes
• Sensor-Based Collision Analysis of Stationary Objects
• Routing With Polygonal Constraints
• Development of a User Interface for Drivers to Indicate the Forthcoming Behavior of Traffic Signals by Integrating a Method for Driving Direction Prediction
• Obstacle-Driven Approach to Identify Acyclic Routes in Building Plans
• Microscopic Traffic Estimation for Green Wave Routing
• Performance Analysis of Dynamic Routing Algorithms Based on Switching Time Forecasts for Traffic Light Systems on the Munich Transport Network
• Concept and Implementation of a Plateau Algorithm for the Determination of Alternative Routes in Buildings
• Compression of Routes Using Persistence
• Approximation of the Shortest Homotopic Path Using Curve Smoothing
• Extension of Privacy-Friendly Route Planning for Continuous Position Updates
• Implementation and Evaluation of Various Map Representations for a Framework for the Identification of Alternative Routes
• Concept and Implementation of a Penalty Algorithm for Indoor Scenarios
• Classification and Sorting of Alternative Routes in Building Plans
• Indexing Trajectories Without Alignment
• Archetypal Analysis in Indoor Navigation Scenarios
• Dynamic Routing in Road Networks Including Switching Time Forecasts for Traffic Lights
• Conceptual Design of a Geo-Social Media Platform for the Mobile Edge
• Method for Distance Measurement Between Trajectories
• Load Optimization in Mobile Networks Through Mobile Edge Computing Using the Example of a Video Conference System

Publications

2024

• S. Zielinski, J. Nüßlein, M. Kölle, T. Gabor, C. Linnhoff-Popien, and S. Feld, „Solving Max-3SAT Using QUBO Approximation,“ arXiv preprint arXiv:2409.15891, 2024.
  [BibTeX]

  @article{zielinski2024solving,
  title={Solving Max-3SAT Using QUBO Approximation},
  author={Zielinski, Sebastian and N{\"u}{\ss}lein, Jonas and K{\"o}lle, Michael and Gabor, Thomas and Linnhoff-Popien, Claudia and Feld, Sebastian},
  journal={arXiv preprint arXiv:2409.15891},
  year={2024}
  }

• S. Zielinski, M. Benkard, J. Nüßlein, C. Linnhoff-Popien, and S. Feld, „SATQUBOLIB: A Python Framework for Creating and Benchmarking (Max-) 3SAT QUBOs,“ in International Conference on Innovations for Community Services, 2024, p. 48–66.
  [BibTeX]

  @inproceedings{zielinski2024satqubolib,
  title={SATQUBOLIB: A Python Framework for Creating and Benchmarking (Max-) 3SAT QUBOs},
  author={Zielinski, Sebastian and Benkard, Magdalena and N{\"u}{\ss}lein, Jonas and Linnhoff-Popien, Claudia and Feld, Sebastian},
  booktitle={International Conference on Innovations for Community Services},
  pages={48--66},
  year={2024},
  organization={Springer}
  }

• S. Zielinski, M. Zorn, T. Gabor, S. Feld, and C. Linnhoff-Popien, „Using an Evolutionary Algorithm to Create (MAX)-3SAT QUBOs,“ in Proceedings of the Genetic and Evolutionary Computation Conference Companion, New York, NY, USA, 2024, p. 1984–1992. doi:10.1145/3638530.3664153
  [BibTeX] [Download PDF]

  @inproceedings{zielinski24using,
  author = {Zielinski, Sebastian and Zorn, Maximilian and Gabor, Thomas and Feld, Sebastian and Linnhoff-Popien, Claudia},
  title = {Using an Evolutionary Algorithm to Create (MAX)-3SAT QUBOs},
  year = {2024},
  isbn = {9798400704956},
  publisher = {Association for Computing Machinery},
  address = {New York, NY, USA},
  url = {https://doi.org/10.1145/3638530.3664153},
  doi = {10.1145/3638530.3664153},
  booktitle = {Proceedings of the Genetic and Evolutionary Computation Conference Companion},
  pages = {1984–1992},
  numpages = {9},
  keywords = {QUBO, (MAX)-3SAT, combinatorial optimization, evolutionary algorithm},
  location = {Melbourne, VIC, Australia},
  series = {GECCO '24 Companion}
  }

2023

• P. Stougiannidis, J. Stein, D. Bucher, S. Zielinski, C. Linnhoff-Popien, and S. Feld, „Approximative lookup-tables and arbitrary function rotations for facilitating NISQ-implementations of the HHL and beyond,“ in 2023 IEEE International Conference on Quantum Computing and Engineering (QCE), 2023, p. 151–160.
  [BibTeX]

  @inproceedings{stougiannidis2023approximative,
  title={Approximative lookup-tables and arbitrary function rotations for facilitating NISQ-implementations of the HHL and beyond},
  author={Stougiannidis, Petros and Stein, Jonas and Bucher, David and Zielinski, Sebastian and Linnhoff-Popien, Claudia and Feld, Sebastian},
  booktitle={2023 IEEE International Conference on Quantum Computing and Engineering (QCE)},
  volume={1},
  pages={151--160},
  year={2023},
  organization={IEEE}
  }

• J. Nüßlein, S. Zielinski, C. Linnhoff-Popien, and S. Feld, „Solving (Max) 3-SAT via Quadratic Unconstrained Binary Optimization,“ in Computational Science – ICCS 2023, 2023.
  [BibTeX]

  @inproceedings{nuessleinICCS23,
  author = {Jonas N{\"u}{\ss}lein and Sebastian Zielinski and Claudia Linnhoff-Popien and Sebastian Feld},
  title = {Solving (Max) 3-SAT via Quadratic Unconstrained Binary Optimization},
  year = {2023},
  publisher = {Springer Nature Switzerland},
  booktitle = {Computational Science -- ICCS 2023},
  location = {Lisbon, Portugal},
  eprint  = {https://doi.org/10.1007/978-3-031-36030-5_3},
  }

• S. Zielinski, J. Nüßlein, J. Stein, T. Gabor, C. Linnhoff-Popien, and S. Feld, „Pattern QUBOs: Algorithmic Construction of 3SAT-to-QUBO Transformations,“ Electronics, 2023. doi:https://doi.org/10.3390/electronics12163492
  [BibTeX]

  @article{zielinskiPatternQUBOMDPI23,
  title={Pattern QUBOs: Algorithmic Construction of 3SAT-to-QUBO Transformations},
  author={Sebastian Zielinski and Jonas N{\"u}{\ss}lein and Jonas Stein and Thomas Gabor and Claudia Linnhoff-Popien and Sebastian Feld},
  journal={Electronics},
  year={2023},
  doi ={https://doi.org/10.3390/electronics12163492},
  eprint={https://www.mdpi.com/2079-9292/12/16/3492},
  }

• S. Zielinski, J. Nüßlein, J. Stein, T. Gabor, C. Linnhoff-Popien, and S. Feld, „Influence of Different 3SAT-to-QUBO Transformations on the Solution Quality of Quantum Annealing: A Benchmark Study,“ in GECCO ’23 Companion: Proceedings of the Companion Conference on Genetic and Evolutionary Computation, 2023.
  [BibTeX]

  @inproceedings{zielinskiGECCO23,
  author = {Sebastian Zielinski and Jonas N{\"u}{\ss}lein and Jonas Stein and Thomas Gabor and Claudia Linnhoff-Popien and Sebastian Feld},
  title = {Influence of Different 3SAT-to-QUBO Transformations on the Solution Quality of Quantum Annealing: A Benchmark Study},
  year = {2023},
  publisher = {ACM},
  booktitle = {GECCO '23 Companion: Proceedings of the Companion Conference on Genetic and Evolutionary Computation},
  location = {Lisbon, Portugal},
  eprint  = {https://dl.acm.org/doi/abs/10.1145/3583133.3596330},
  }

2022

• C. Roch, D. Ratke, J. Nüßlein, T. Gabor, and S. Feld, „The Effect of Penalty Factors of Constrained Hamiltonians on the Eigenspectrum in Quantum Annealing,“ ACM Transactions on Quantum Computing, 2022. doi:10.1145/3577202
  [BibTeX]

  @article{10.1145/3577202,
  author = {Roch, Christoph and Ratke, Daniel and Nüßlein, Jonas and Gabor, Thomas and Feld, Sebastian},
  title = {The Effect of Penalty Factors of Constrained Hamiltonians on the Eigenspectrum in Quantum Annealing},
  year = {2022},
  publisher = {Association for Computing Machinery},
  address = {New York, NY, USA},
  issn = {2643-6809},
  doi = {10.1145/3577202},
  journal = {ACM Transactions on Quantum Computing},
  month = {12},
  keywords = {Quantum annealing, penalty factor, optimization, clustering, artificial neural network, d-wave systems, constrained hamiltonian, minimal spectral gap, regression}
  }

• J. Lang, S. Zielinski, and S. Feld, „Strategic Portfolio Optimization Using Simulated, Digital, and Quantum Annealing,“ Applied Sciences, vol. 12, iss. 23, p. 12288, 2022.
  [BibTeX]

  @article{lang2022strategic,
  title={Strategic Portfolio Optimization Using Simulated, Digital, and Quantum Annealing},
  author={Lang, Jonas and Zielinski, Sebastian and Feld, Sebastian},
  journal={Applied Sciences},
  volume={12},
  number={23},
  pages={12288},
  year={2022},
  publisher={MDPI}
  }

2020

• C. Roch, A. Impertro, T. Phan, T. Gabor, S. Feld, and C. Linnhoff-Popien, „Cross entropy hyperparameter optimization for constrained problem Hamiltonians applied to QAOA,“ in 2020 International Conference on Rebooting Computing (ICRC), 2020, p. 50–57.
  [BibTeX]

  @inproceedings{roch2020cross,
  title = {Cross entropy hyperparameter optimization for constrained problem Hamiltonians applied to QAOA},
  author = {Roch, Christoph and Impertro, Alexander and Phan, Thomy and Gabor, Thomas and Feld, Sebastian and Linnhoff-Popien, Claudia},
  booktitle = {2020 International Conference on Rebooting Computing (ICRC)},
  pages = {50--57},
  year = {2020},
  organization = {IEEE}
  }

• C. Roch, T. Phan, S. Feld, R. Müller, T. Gabor, C. Hahn, and C. Linnhoff-Popien, „A Quantum Annealing Algorithm for Finding Pure Nash Equilibria in Graphical Games,“ in 20th International Conference on Computational Science (ICCS 2020), 2020, p. 12. doi:10.1007/978-3-030-50433-5_38
  [BibTeX] [Download PDF]

  @inproceedings{roch2020quantum,
  author = {Christoph Roch and Thomy Phan and Sebastian Feld and Robert Müller and Thomas Gabor and Carsten Hahn and Claudia Linnhoff-Popien},
  title = {A Quantum Annealing Algorithm for Finding Pure Nash Equilibria in Graphical Games},
  booktitle = {20th International Conference on Computational Science (ICCS 2020)},
  year = {2020},
  month = {June},
  pages = {12},
  url = {https://www.iccs-meeting.org/archive/iccs2020/papers/121420466.pdf},
  doi = {10.1007/978-3-030-50433-5_38}
  }

• I. Sax, S. Feld, S. Zielinski, T. Gabor, C. Linnhoff-Popien, and W. Mauerer, „Approximate Approximation on a Quantum Annealer,“ in 17th ACM International Conference on Computing Frontiers (ACM CF 2020), 2020, p. 9. doi:10.1145/3387902.3392635
  [BibTeX] [Download PDF]

  @inproceedings{sax2020approximate,
  author = {Irmengard Sax and Sebastian Feld and Sebastian Zielinski and Thomas Gabor and Claudia Linnhoff-Popien and Wolfgang Mauerer},
  title = {Approximate Approximation on a Quantum Annealer},
  booktitle = {17th ACM International Conference on Computing Frontiers (ACM CF 2020)},
  url = {https://arxiv.org/abs/2004.09267},
  year = {2020},
  month = {May},
  pages = {9},
  doi = {10.1145/3387902.3392635}
  }

• T. Phan, L. Belzner, K. Schmid, T. Gabor, F. Ritz, S. Feld, and C. Linnhoff-Popien, „A Distributed Policy Iteration Scheme for Cooperative Multi-Agent Policy Approximation,“ Adaptive and Learning Agents Workshop (ALA) @ AAMAS 2020, 2020.
  [BibTeX] [Download PDF]

  @article{phan2020distributed,
  title = {A Distributed Policy Iteration Scheme for Cooperative Multi-Agent Policy Approximation},
  author = {Phan, Thomy and Belzner, Lenz and Schmid, Kyrill and Gabor, Thomas and Ritz, Fabian and Feld, Sebastian and Linnhoff-Popien, Claudia},
  journal = {Adaptive and Learning Agents Workshop (ALA) @ AAMAS 2020},
  year = {2020},
  url = {https://ala2020.vub.ac.be/papers/ALA2020_paper_36.pdf},
  owner = {tphan}
  }

• S. Illium, P. A. Friese, R. Müller, and S. Feld, „What to do in the Meantime: A Service Coverage Analysis for Parked Autonomous Vehicles,“ AGILE: GIScience Series, vol. 1, p. 7, 2020. doi:10.5194/agile-giss-1-7-2020
  [BibTeX] [Download PDF]

  @article{agile-giss-1-7-2020,
  author = {Illium, S. and Friese, P. A. and M\"uller, R. and Feld, S.},
  title = {What to do in the Meantime: A Service Coverage Analysis for Parked Autonomous Vehicles},
  journal = {AGILE: GIScience Series},
  volume = {1},
  year = {2020},
  pages = {7},
  url = {https://agile-giss.copernicus.org/articles/1/7/2020/},
  doi = {10.5194/agile-giss-1-7-2020}
  }

• T. Gabor, L. Suenkel, F. Ritz, T. Phan, L. Belzner, C. Roch, S. Feld, and C. Linnhoff-Popien, „The Holy Grail of Quantum Artificial Intelligence: Challenges in Accelerating the Machine Learning Pipeline,“ in Accepted at the 1st International Workshop on Quantum Software Engineering (QSE at ICSE), 2020.
  [BibTeX]

  @inproceedings{gabor2020the,
  author = {Thomas Gabor and Leo Suenkel and Fabian Ritz and Thomy Phan and Lenz Belzner and Christoph Roch and Sebastian Feld and Claudia Linnhoff-Popien},
  title = {The Holy Grail of Quantum Artificial Intelligence: Challenges in Accelerating the Machine Learning Pipeline},
  booktitle = {Accepted at the 1st International Workshop on Quantum Software Engineering (QSE at ICSE)},
  year = {2020},
  owner = {tgabor}
  }

• T. Gabor, S. Feld, H. Safi, T. Phan, and C. Linnhoff-Popien, „Insights on Training Neural Networks for QUBO Tasks,“ in Accepted at the 1st International Workshop on Quantum Software Engineering (QSE at ICSE), 2020.
  [BibTeX]

  @inproceedings{gabor2020insights,
  author = {Thomas Gabor and Sebastian Feld and Hila Safi and Thomy Phan and Claudia Linnhoff-Popien},
  title = {Insights on Training Neural Networks for QUBO Tasks},
  booktitle = {Accepted at the 1st International Workshop on Quantum Software Engineering (QSE at ICSE)},
  year = {2020},
  owner = {tgabor}
  }

• S. Feld, C. Roch, K. Geirhos, and T. Gabor, „Approximating Archetypal Analysis Using Quantum Annealing,“ in Accepted at the 28th European Symposium on Artificial Neural Networks, Computational Intelligence and Machine Learning (ESANN 2020), 2020.
  [BibTeX]

  @inproceedings{feld2020approximating,
  author = {Sebastian Feld and Christoph Roch and Katja Geirhos and Thomas Gabor},
  title = {Approximating Archetypal Analysis Using Quantum Annealing},
  booktitle = {Accepted at the 28th European Symposium on Artificial Neural Networks, Computational Intelligence and Machine Learning (ESANN 2020)},
  year = {2020},
  owner = {sfeld}
  }

• M. Friedrich, C. Roch, S. Feld, C. Hahn, and P. Fayolle, „A Flexible Pipeline for the Optimization of Construction Trees,“ in Proceedings of the 28th International Conference on Computer Graphics, Visualization and Computer Vision (WSCG), 2020.
  [BibTeX]

  @inproceedings{friedrich2020csg-optim,
  author = {Friedrich, Markus and Roch, Christoph and Feld, Sebastian and Hahn, Carsten and Fayolle, Pierre-Alain},
  title = {A Flexible Pipeline for the Optimization of Construction Trees},
  booktitle = {Proceedings of the 28th International Conference on Computer Graphics, Visualization and Computer Vision (WSCG)},
  year = {2020},
  owner = {mfriedrich}
  }

• C. Hahn, T. Phan, S. Feld, C. Roch, F. Ritz, A. Sedlmeier, T. Gabor, and C. Linnhoff-Popien, „Nash Equilibria in Multi-Agent Swarms,“ in 12th International Conference on Agents and Artificial Intelligence (ICAART 2020), 2020.
  [BibTeX]

  @inproceedings{hahn2020nash,
  author = {Carsten Hahn and Thomy Phan and Sebastian Feld and Christoph Roch and Fabian Ritz and Andreas Sedlmeier and Thomas Gabor and Claudia Linnhoff-Popien},
  title = {Nash Equilibria in Multi-Agent Swarms},
  booktitle = {12th International Conference on Agents and Artificial Intelligence (ICAART 2020)},
  year = {2020},
  owner = {chahn}
  }

• S. Feld, C. Roch, T. Gabor, M. To, and C. Linnhoff-Popien, „The Dynamic Time Warping Distance Measure as QUBO Formulation,“ in IEEE 5th International Conference on Computer and Communication Systems (ICCCS 2020), 2020.
  [BibTeX]

  @inproceedings{feld2020DTWQubo,
  title = {The Dynamic Time Warping Distance Measure as QUBO Formulation},
  author = {Sebastian Feld and Christoph Roch and Thomas Gabor and M. To and Claudia Linnhoff-Popien},
  booktitle = {IEEE 5th International Conference on Computer and Communication Systems (ICCCS 2020)},
  year = {2020},
  organization = {IEEE}
  }

• T. Gabor, S. Zielinski, C. Roch, S. Feld, and C. Linnhoff-Popien, „The UQ Platform: A Unified Approach To Quantum Annealing,“ in IEEE 5th International Conference on Computer and Communication Systems (ICCCS 2020), 2020.
  [BibTeX]

  @inproceedings{gabor2020UQ,
  title = {The UQ Platform: A Unified Approach To Quantum Annealing},
  author = {Thomas Gabor and Sebastian Zielinski and Christoph Roch and Sebastian Feld and Claudia Linnhoff-Popien},
  booktitle = {IEEE 5th International Conference on Computer and Communication Systems (ICCCS 2020)},
  year = {2020},
  organization = {IEEE}
  }

• C. Hahn, S. Feld, and H. Schroter, „Predictive Collision Management for Time and Risk Dependent Path Planning,“ in 28th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (SIGSPATIAL 2020), 2020.
  [BibTeX]

  @inproceedings{hahn2020sigspatial,
  author = {Hahn, Carsten and Feld, Sebastian and Schroter, Hannes},
  title = {Predictive Collision Management for Time and Risk Dependent Path Planning},
  booktitle = {28th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (SIGSPATIAL 2020)},
  year = {2020},
  organization = {ACM},
  owner = {chahn}
  }

2019

• S. Feld and C. Linnhoff-Popien, Quantum Technology and Optimization Problems: First International Workshop, QTOP 2019, Munich, Germany, March 18, 2019, Proceedings, Springer, 2019, vol. 11413.
  [BibTeX]

  @book{feld2019quantum,
  title = {Quantum Technology and Optimization Problems: First International Workshop, QTOP 2019, Munich, Germany, March 18, 2019, Proceedings},
  author = {Feld, Sebastian and Linnhoff-Popien, Claudia},
  volume = {11413},
  year = {2019},
  publisher = {Springer}
  }

• C. Hahn, S. Feld, M. Zierl, and C. Linnhoff-Popien, „Dynamic Path Planning with Stable Growing Neural Gas,“ in 11th International Conference on Agents and Artificial Intelligence (ICAART 2019), 2019.
  [BibTeX]

  @inproceedings{hahn2019dynamic,
  author = {Carsten Hahn and Sebastian Feld and Manuel Zierl and Claudia Linnhoff-Popien},
  title = {Dynamic Path Planning with Stable Growing Neural Gas},
  booktitle = {11th International Conference on Agents and Artificial Intelligence (ICAART 2019)},
  year = {2019},
  owner = {chahn}
  }

• T. Phan, K. Schmid, L. Belzner, T. Gabor, S. Feld, and C. Linnhoff-Popien, „Distributed Policy Iteration for Scalable Approximation of Cooperative Multi-Agent Policies (Extended Abstract),“ in 18th International Conference on Autonomous Agents and Multiagent Systems (AAMAS 2019), 2019.
  [BibTeX] [Download PDF]

  @inproceedings{phan2019distributed,
  author = {Thomy Phan and Kyrill Schmid and Lenz Belzner and Thomas Gabor and Sebastian Feld and Claudia Linnhoff-Popien},
  title = {Distributed Policy Iteration for Scalable Approximation of Cooperative Multi-Agent Policies (Extended Abstract)},
  booktitle = {18th International Conference on Autonomous Agents and Multiagent Systems (AAMAS 2019)},
  year = {2019},
  owner = {tphan},
  url = {https://arxiv.org/pdf/1901.08761.pdf}
  }

• T. Gabor, S. Zielinski, S. Feld, C. Roch, C. Seidel, F. Neukart, I. Galter, W. Mauerer, and C. Linnhoff-Popien, „Assessing Solution Quality of 3SAT on a Quantum Annealing Platform,“ in 1st International Workshop on Quantum Technology and Optimization Problems (QTOP 2019), 2019, p. 23–35.
  [BibTeX]

  @inproceedings{gabor2019assessing,
  author = {Gabor, Thomas and Zielinski, Sebastian and Feld, Sebastian and Roch, Christoph and Seidel, Christian and Neukart, Florian and Galter, Isabella and Mauerer, Wolfgang and Linnhoff-Popien, Claudia},
  title = {Assessing Solution Quality of 3SAT on a Quantum Annealing Platform},
  booktitle = {1st International Workshop on Quantum Technology and Optimization Problems (QTOP 2019)},
  year = {2019},
  pages = {23--35},
  publisher = {Springer}
  }

• I. Figalist, A. Biesdorf, C. Brand, S. Feld, and M. Kiermeier, „Supporting the DevOps Feedback Loop using Unsupervised Learning,“ in 2019 International Symposium on Innovations in Intelligent Systems and Applications (INISTA), 2019.
  [BibTeX]

  @inproceedings{figalist2019supporting,
  author = {Figalist, Iris and Biesdorf, Andreas and Brand, Christoph and Feld, Sebastian and Kiermeier, Marie},
  title = {Supporting the DevOps Feedback Loop using Unsupervised Learning},
  booktitle = {2019 International Symposium on Innovations in Intelligent Systems and Applications (INISTA)},
  year = {2019},
  organization = {IEEE},
  owner = {sfeld}
  }

• S. Feld, A. Sedlmeier, M. Friedrich, J. Franz, and L. Belzner, „Bayesian Surprise in Indoor Environments,“ in 27th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (SIGSPATIAL ’19), 2019.
  [BibTeX]

  @inproceedings{feld2019bayesian,
  author = {Feld, Sebastian and Sedlmeier, Andreas and Friedrich, Markus and Franz, Jan and Belzner, Lenz},
  title = {Bayesian Surprise in Indoor Environments},
  booktitle = {27th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (SIGSPATIAL ’19)},
  year = {2019},
  organization = {ACM}
  }

• I. Sax, S. Feld, S. Zielinski, T. Gabor, C. Linnhoff-Popien, and W. Mauerer, „Torwards understanding Approximation Complexity on a Quantum Annealer (Extended Abstract),“ in 1st International Symposium on Applied Artificial Intelligence (ISAAI’19), 2019.
  [BibTeX]

  @inproceedings{sax2019towards,
  author = {Irmi Sax and Sebastian Feld and Sebastian Zielinski and Thomas Gabor and Claudia Linnhoff-Popien and Wolfgang Mauerer},
  title = {Torwards understanding Approximation Complexity on a Quantum Annealer (Extended Abstract)},
  booktitle = {1st International Symposium on Applied Artificial Intelligence (ISAAI'19)},
  year = {2019},
  owner = {isax}
  }

• S. Feld, „Gerrymandering as a Combinatorial Optimization Problem (Extended Abstract),“ in 1st International Symposium on Applied Artificial Intelligence (ISAAI’19), 2019.
  [BibTeX]

  @inproceedings{feld2019gerrymandering,
  author = {Sebastian Feld},
  title = {Gerrymandering as a Combinatorial Optimization Problem (Extended Abstract)},
  booktitle = {1st International Symposium on Applied Artificial Intelligence (ISAAI'19)},
  year = {2019},
  owner = {sfeld}
  }

• S. Feld, C. Roch, T. Gabor, C. Seidel, F. Neukart, I. Galter, W. Mauerer, and C. Linnhoff-Popien, „A Hybrid Solution Method for the Capacitated Vehicle Routing Problem Using a Quantum Annealer,“ in Frontiers in ICT, 2019, p. 1–13.
  [BibTeX]

  @inproceedings{feld2019hybrid,
  author = {Sebastian Feld and Christoph Roch and Thomas Gabor and Christian Seidel and Florian Neukart and Isabella Galter and Wolfgang Mauerer and Claudia Linnhoff-Popien},
  title = {A Hybrid Solution Method for the Capacitated Vehicle Routing Problem Using a Quantum Annealer},
  booktitle = {Frontiers in ICT},
  year = {2019},
  volume = {6},
  pages = {1--13},
  owner = {sfeld}
  }

• S. Feld and C. Linnhoff-Popien, Quantum Technology and Optimization Problems: First International Workshop, QTOP 2019, Munich, Germany, March 18, 2019, Proceedings, Springer, 2019, vol. 11413.
  [BibTeX]

  @book{feld2019quantum,
  title = {Quantum Technology and Optimization Problems: First International Workshop, QTOP 2019, Munich, Germany, March 18, 2019, Proceedings},
  publisher = {Springer},
  year = {2019},
  author = {Feld, Sebastian and Linnhoff-Popien, Claudia},
  volume = {11413}
  }

• S. Feld, Alternative Routen in komplexen Umgebungen: Werkzeuge für ortsbezogene Anwendungen und Dienste, Springer-Verlag, 2019.
  [BibTeX]

  @book{feld2019alternative,
  title = {Alternative Routen in komplexen Umgebungen: Werkzeuge f{\"u}r ortsbezogene Anwendungen und Dienste},
  publisher = {Springer-Verlag},
  year = {2019},
  author = {Feld, Sebastian}
  }

2018

• M. Werner and S. Feld, „Successful Data Science Is a Communication Challenge,“ in Digital Marketplaces Unleashed, Springer, 2018, p. 583–592.
  [BibTeX]

  @incollection{werner2018successful,
  title = {Successful Data Science Is a Communication Challenge},
  author = {Werner, Martin and Feld, Sebastian},
  booktitle = {Digital Marketplaces Unleashed},
  publisher = {Springer},
  year = {2018},
  pages = {583--592},
  owner = {sfeld},
  timestamp = {2017.09.20}
  }

• A. Sedlmeier and S. Feld, „Discovering and Learning Recurring Structures in Building Floor Plans,“ in LBS 2018: 14th International Conference on Location Based Services, 2018, p. 151–170.
  [BibTeX]

  @inproceedings{sedlmeier2018discovering,
  author = {Sedlmeier, Andreas and Feld, Sebastian},
  title = {Discovering and Learning Recurring Structures in Building Floor Plans},
  booktitle = {LBS 2018: 14th International Conference on Location Based Services},
  year = {2018},
  pages = {151--170},
  publisher = {Springer},
  owner = {asedlmeier}
  }

• C. Hahn and S. Feld, „Collision Avoidance using Intuitive Physics,“ in 2018 International Symposium on Innovations in Intelligent Systems and Applications (INISTA), 2018.
  [BibTeX]

  @inproceedings{hahn2018collision,
  author = {Hahn, Carsten and Feld, Sebastian},
  title = {Collision Avoidance using Intuitive Physics},
  booktitle = {2018 International Symposium on Innovations in Intelligent Systems and Applications (INISTA)},
  year = {2018},
  organization = {IEEE},
  owner = {chahn}
  }

• M. Friedrich, S. Feld, T. Phan, and P. Fayolle, „Accelerating Evolutionary Construction Tree Extraction via Graph Partitioning,“ in Proceedings of the 26th International Conference on Computer Graphics, Visualization and Computer Vision (WSCG), 2018.
  [BibTeX]

  @inproceedings{friedrich2018accelerating,
  author = {Friedrich, Markus and Feld, Sebastian and Phan, Thomy and Fayolle, Pierre-Alain},
  title = {Accelerating Evolutionary Construction Tree Extraction via Graph Partitioning},
  booktitle = {Proceedings of the 26th International Conference on Computer Graphics, Visualization and Computer Vision (WSCG)},
  year = {2018},
  owner = {mfriedrich}
  }

• M. Kiermeier and S. Feld, „Visual Analytics for Root Cause Analysis in Self-Organizing Industrial Systems,“ in IEEE 16th International Conference on Industrial Informatics (INDIN 2018), 2018, p. 315–320.
  [BibTeX]

  @inproceedings{INDIN_visual_analytics,
  author = {Kiermeier, Marie and Feld, Sebastian},
  title = {Visual Analytics for Root Cause Analysis in Self-Organizing Industrial Systems},
  booktitle = {IEEE 16th International Conference on Industrial Informatics (INDIN 2018)},
  year = {2018},
  pages = {315--320},
  organization = {IEEE}
  }

• M. Kiermeier, S. Feld, T. Phan, and C. Linnhoff-Popien, „Anomaly Detection in Spatial Layer Models of Autonomous Agents,“ in 18th International Conference on Intelligent Data Engineering and Automated Learning (IDEAL 2018), 2018.
  [BibTeX]

  @inproceedings{IDEAL_spatial_layer_models,
  author = {Kiermeier, Marie and Feld, Sebastian and Phan, Thomy and Linnhoff-Popien, Claudia},
  title = {Anomaly Detection in Spatial Layer Models of Autonomous Agents},
  booktitle = {18th International Conference on Intelligent Data Engineering and Automated Learning (IDEAL 2018)},
  year = {2018},
  organization = {Springer}
  }

• S. Feld, S. Illium, A. Sedlmeier, and L. Belzner, „Trajectory annotation using sequences of spatial perception,“ in 26th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (SIGSPATIAL ’18), 2018, p. 1–10. doi:https://doi.org/10.1145/3274895.3274968
  [BibTeX]

  @inproceedings{feld2018trajectory,
  author = {Feld, Sebastian and Illium, Steffen and Sedlmeier, Andreas and Belzner, Lenz},
  title = {Trajectory annotation using sequences of spatial perception},
  booktitle = {26th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (SIGSPATIAL ’18)},
  year = {2018},
  pages = {1--10},
  organization = {ACM},
  doi = {https://doi.org/10.1145/3274895.3274968}
  }

• S. Feld, M. Friedrich, and C. Linnhoff-Popien, „Optimizing Geometry Compression using Quantum Annealing,“ in IEEE Workshop on Quantum Communications and Information Technology 2018 (IEEE QCIT 2018), 2018, p. 1–6.
  [BibTeX]

  @inproceedings{feld2018optimizing,
  author = {Feld, Sebastian and Friedrich, Markus and Linnhoff-Popien, Claudia},
  title = {Optimizing Geometry Compression using Quantum Annealing},
  booktitle = {IEEE Workshop on Quantum Communications and Information Technology 2018 (IEEE QCIT 2018)},
  year = {2018},
  pages = {1--6}
  }

• S. Feld, „Alternative Routen in komplexen Umgebungen,“ PhD Thesis, 2018.
  [BibTeX]

  @phdthesis{feld2018alternative,
  author = {Feld, Sebastian},
  title = {Alternative Routen in komplexen Umgebungen},
  school = {LMU},
  year = {2018}
  }

• A. Sedlmeier and S. Feld, „Learning indoor space perception,“ Journal of Location Based Services, pp. 1-36, 2018. doi:10.1080/17489725.2018.1539255
  [BibTeX] [Download PDF]

  @article{sedlmeier2018learning,
  author = {Andreas Sedlmeier and Sebastian Feld},
  title = {Learning indoor space perception},
  journal = {Journal of Location Based Services},
  year = {2018},
  volume = {0},
  number = {0},
  pages = {1-36},
  doi = {10.1080/17489725.2018.1539255},
  owner = {asedlmeier},
  url = {https://doi.org/10.1080/17489725.2018.1539255}
  }

2017

• C. Linnhoff-Popien, S. Feld, M. Werner, and M. Schönfeld, „Innovationszentrum Mobiles Internet des ZD.B – Methoden der Digitalisierung in der Arbeitswelt,“ in 50 Jahre Universitäts-Informatik in München, Springer Vieweg, Berlin, Heidelberg, 2017, p. 87–95.
  [BibTeX]

  @incollection{linnhoff2017innovationszentrum,
  title = {Innovationszentrum Mobiles Internet des ZD.B -- Methoden der Digitalisierung in der Arbeitswelt},
  author = {Claudia Linnhoff-Popien and Sebastian Feld and Martin Werner and Mirco Schönfeld},
  booktitle = {50 Jahre Universitäts-Informatik in München},
  publisher = {Springer Vieweg, Berlin, Heidelberg},
  year = {2017},
  pages = {87--95},
  owner = {clinnhoff},
  timestamp = {2017.09.12}
  }

• M. Kiermeier, S. Feld, and C. Linnhoff-Popien, „Root Cause Analysis for Global Anomalous Events in Self-Organizing Industrial Systems,“ in Proceedings of the 21th IEEE International Conference on Intelligent Engineering Systems (INES), 2017.
  [BibTeX]

  @inproceedings{kiermeier2017root,
  author = {Kiermeier, Marie and Feld, Sebastian and Linnhoff-Popien, Claudia},
  title = {Root Cause Analysis for Global Anomalous Events in Self-Organizing Industrial Systems},
  booktitle = {Proceedings of the 21th IEEE International Conference on Intelligent Engineering Systems (INES)},
  year = {2017},
  publisher = {IEEE},
  owner = {mkiermeier}
  }

2016

• M. T. Beck, S. Feld, C. Linnhhoff-Popien, and U. Pützschler, „Mobile Edge Computing,“ Informatik-Spektrum, vol. 39, iss. 2, pp. 108-114, 2016.
  [BibTeX] [Download PDF]

  @article{Beck2016Mobile,
  title = {Mobile Edge Computing},
  author = {Michael Till Beck and Sebastian Feld and Claudia Linnhhoff-Popien and Uwe Pützschler},
  journal = {Informatik-Spektrum},
  year = {2016},
  number = {2},
  pages = {108-114},
  volume = {39},
  owner = {mbeck},
  timestamp = {2016.04.29},
  url = {http://rd.springer.com/article/10.1007/s00287-016-0957-6}
  }

• A. Ebert, S. Feld, and F. Dorfmeister, „Segmented and Directional Impact Detection for Parked Vehicles using Mobile Devices,“ in 23rd International Conference on Systems, Signals and Image Processing (IWSSIP 2016), 2016.
  [BibTeX]

  @inproceedings{ebert2016segmented,
  title = {Segmented and Directional Impact Detection for Parked Vehicles using Mobile Devices},
  author = {André Ebert and Sebastian Feld and Florian Dorfmeister},
  booktitle = {23rd International Conference on Systems, Signals and Image Processing (IWSSIP 2016)},
  year = {2016},
  publisher = {IEEE},
  owner = {aebert},
  timestamp = {2016.07.01}
  }

• S. Feld, C. Linnhhoff-Popien, and R. Göttmann, „Wo bleibt die Sehnsucht nach dem Neuen?,“ Informatik-Spektrum, vol. 39, iss. 2, pp. 105-107, 2016.
  [BibTeX] [Download PDF]

  @article{Feld2016Wo,
  title = {Wo bleibt die Sehnsucht nach dem Neuen?},
  author = {Sebastian Feld and Claudia Linnhhoff-Popien and Rainer Göttmann},
  journal = {Informatik-Spektrum},
  year = {2016},
  number = {2},
  pages = {105-107},
  volume = {39},
  owner = {sfeld},
  timestamp = {2016.04.29},
  url = {http://rd.springer.com/article/10.1007/s00287-016-0959-4}
  }

• S. Feld, H. Lyu, and A. Keler, „Identifying Divergent Building Structures Using Fuzzy Clustering of Isovist Features,“ in 13th International Conference on Location-Based Services (LBS 2016), 2016.
  [BibTeX]

  @inproceedings{feld2016identifying,
  author = {Sebastian Feld and Hao Lyu and Andreas Keler},
  title = {Identifying Divergent Building Structures Using Fuzzy Clustering of Isovist Features},
  booktitle = {13th International Conference on Location-Based Services (LBS 2016)},
  year = {2016},
  owner = {sfeld}
  }

• S. Feld, M. Schönfeld, and M. Werner, „Traversing Bitcoin’s P2P network: Insights into the structure of a decentralized currency,“ International Journal of Computational Science and Engineering (IJCSE), Special Issue on Security and Trust Issues in Peer-to-Peer Networks, vol. 13, iss. 2, pp. 122-131, 2016.
  [BibTeX] [Abstract] [Download PDF]
  

  Bitcoin has become increasingly important for several years. While being declared dead in the meantime, it got a boost in 2011. The exchange rate increased from \$14 in January 2013 up to \$240 in April 2013 and even \$900 in early 2014. Lots of existing work addresses the analysis of the publicly available transaction graph. There are evaluations of the user’s anonymity and privacy, but no proper measurements of the underlying network. In this paper, we present novel insights about Bitcoin’s peer-to-peer network, with a focus on its distribution among distinct autonomous systems. The resilience of the Bitcoin ecosystem, the unambiguousness of the blockchain in use, the propagation and verification of transaction blocks, but also the anonymity of Bitcoin’s users depend on the structure of the global peer-to-peer network. Our work is the first thorough analysis of Bitcoin’s underlying peer-to-peer network, especially with regard to its distribution at the autonomous system level. We traversed Bitcoin’s peer-to-peer network in a protocol-compliant manner and made statements about the size of the accessible network and the number of clients. This information is useful when modelling the probability of attacks against the user’s privacy or other aspects. Further, we investigated the distribution of the peer-to-peer network on autonomous systems. The concrete form has an impact on the above-mentioned topics, such as vitality, resilience or privacy. Finally, we analysed the mechanism to announce known peers. It turns out that Bitcoin’s peer announcement is not well distributed, affecting information propagation.

  @article{bitcoinjournal,
  title = {Traversing Bitcoin’s P2P network: Insights into the structure of a decentralized currency},
  author = {Sebastian Feld and Mirco Schönfeld and Martin Werner},
  journal = {International Journal of Computational Science and Engineering (IJCSE), Special Issue on Security and Trust Issues in Peer-to-Peer Networks},
  year = {2016},
  number = {2},
  pages = {122-131},
  volume = {13},
  abstract = {Bitcoin has become increasingly important for several years. While being declared dead in the meantime, it got a boost in 2011. The exchange rate increased from \$14 in January 2013 up to \$240 in April 2013 and even \$900 in early 2014. Lots of existing work addresses the analysis of the publicly available transaction graph. There are evaluations of the user's anonymity and privacy, but no proper measurements of the underlying network. In this paper, we present novel insights about Bitcoin's peer-to-peer network, with a focus on its distribution among distinct autonomous systems. The resilience of the Bitcoin ecosystem, the unambiguousness of the blockchain in use, the propagation and verification of transaction blocks, but also the anonymity of Bitcoin's users depend on the structure of the global peer-to-peer network. Our work is the first thorough analysis of Bitcoin's underlying peer-to-peer network, especially with regard to its distribution at the autonomous system level. We traversed Bitcoin's peer-to-peer network in a protocol-compliant manner and made statements about the size of the accessible network and the number of clients. This information is useful when modelling the probability of attacks against the user's privacy or other aspects. Further, we investigated the distribution of the peer-to-peer network on autonomous systems. The concrete form has an impact on the above-mentioned topics, such as vitality, resilience or privacy. Finally, we analysed the mechanism to announce known peers. It turns out that Bitcoin's peer announcement is not well distributed, affecting information propagation.},
  owner = {sfeld},
  url = {http://www.inderscience.com/offer.php?id=78441}
  }

• S. Feld, M. Werner, and C. Linnhoff-Popien, „Approximated Environment Features With Application to Trajectory Annotation,“ in 6th IEEE Symposium Series on Computational Intelligence (IEEE SSCI 2016), 2016.
  [BibTeX]

  @inproceedings{feld2016approximated,
  author = {Sebastian Feld and Martin Werner and Claudia Linnhoff-Popien},
  title = {Approximated Environment Features With Application to Trajectory Annotation},
  booktitle = {6th IEEE Symposium Series on Computational Intelligence (IEEE SSCI 2016)},
  year = {2016},
  owner = {sfeld}
  }

• S. Feld, M. Werner, and C. Linnhoff-Popien, „Criteria for Selecting Small Sets of Alternative Routes in Free Space Scenarios,“ in 13th International Conference on Location-Based Services (LBS 2016), 2016.
  [BibTeX]

  @inproceedings{feld2016criteria,
  author = {Sebastian Feld and Martin Werner and Claudia Linnhoff-Popien},
  title = {Criteria for Selecting Small Sets of Alternative Routes in Free Space Scenarios},
  booktitle = {13th International Conference on Location-Based Services (LBS 2016)},
  year = {2016},
  owner = {sfeld}
  }

2015

• M. Beck, S. Feld, and T. Schimper, „Vom Zugangs- zum Dienstanbieter: Wie Mobilfunkprovider das Internet der Zukunft mitgestalten können,“ in Marktplätze im Umbruch – Digitale Strategien fuer Services im Mobilen Internet, C. Linnhoff-Popien, M. Zaddach, and A. Grahl, Eds., Springer Berlin Heidelberg, 2015, pp. 123-131.
  [BibTeX] [Abstract]
  

  Dieser Beitrag beleuchtet, inwieweit sich Mobilfunkprovider in den letzten Jahren zu Infrastrukturprovidern gewandelt haben, die primär Datenvolumen an externe Dienste weiterleiten, an denen sie selbst finanziell nicht beteiligt sind. Am Beispiel der Mobile Edge Computing Technologie wird erörtert, wie diesem Trend entgegengewirkt werden kann und der Wandel vom Infrastrukturprovider hin zum Dienstanbieter gelingen kann.

  @incollection{marktplaetzebuch,
  title = {Vom Zugangs- zum Dienstanbieter: Wie Mobilfunkprovider das Internet der Zukunft mitgestalten können},
  author = {Michael Beck and Sebastian Feld and Thomas Schimper},
  booktitle = {Marktplätze im Umbruch - Digitale Strategien fuer Services im Mobilen Internet},
  publisher = {Springer Berlin Heidelberg},
  year = {2015},
  editor = {Claudia Linnhoff-Popien and Michael Zaddach and Andreas Grahl},
  pages = {123-131},
  series = {Xpert.press},
  abstract = {Dieser Beitrag beleuchtet, inwieweit sich Mobilfunkprovider in den letzten Jahren zu Infrastrukturprovidern gewandelt haben, die primär Datenvolumen an externe Dienste weiterleiten, an denen sie selbst finanziell nicht beteiligt sind. Am Beispiel der Mobile Edge Computing Technologie wird erörtert, wie diesem Trend entgegengewirkt werden kann und der Wandel vom Infrastrukturprovider hin zum Dienstanbieter gelingen kann.},
  owner = {mbeck}
  }

• M. T. Beck, S. Feld, A. Fichtner, C. Linnhoff-Popien, and T. Schimper, „ME-VoLTE: Network Functions for Energy-Efficient Video Transcoding at the Mobile Edge,“ in 18th International Conference on Intelligence in Next Generation Networks (ICIN 2015), 2015, pp. 38-44. doi:http://dx.doi.org/10.1109/ICIN.2015.7073804
  [BibTeX] [Abstract]
  

  Encoding multimedia streams of video calls is a very compute-intense task that significantly decreases battery lifetime of mobile phones. This paper introduces an approach to reduce power consumption of mobile phones by offloading video encoding efforts from mobile devices to external services. These services are hosted on servers co-located with cellular base stations. The paper describes how these services are integrated into the existing mobile network architecture and presents a communication protocol for negotiating offloading settings. First measurement results indicate that power consumption of mobile devices is reduced by approximately 13\%.

  @inproceedings{mecsip,
  title = {ME-VoLTE: Network Functions for Energy-Efficient Video Transcoding at the Mobile Edge},
  author = {Michae Till Beck and Sebastian Feld and Andreas Fichtner and Claudia Linnhoff-Popien and Thomas Schimper},
  booktitle = {18th International Conference on Intelligence in Next Generation Networks (ICIN 2015)},
  year = {2015},
  pages = {38-44},
  publisher = {IEEE},
  abstract = {Encoding multimedia streams of video calls is a very compute-intense task that significantly decreases battery lifetime of mobile phones. This paper introduces an approach to reduce power consumption of mobile phones by offloading video encoding efforts from mobile devices to external services. These services are hosted on servers co-located with cellular base stations. The paper describes how these services are integrated into the existing mobile network architecture and presents a communication protocol for negotiating offloading settings. First measurement results indicate that power consumption of mobile devices is reduced by approximately 13\%.},
  doi = {http://dx.doi.org/10.1109/ICIN.2015.7073804},
  owner = {mbeck}
  }

• A. Ebert, S. Feld, and M. Werner, „Nuanced Collision Detection for Parked Vehicles,“ in 12. GI/ITG KuVS Fachgespräch Ortsbezogene Anwendungen und Dienste (LBAS 2015), 2015.
  [BibTeX]

  @inproceedings{collisiondetection15,
  title = {Nuanced Collision Detection for Parked Vehicles},
  author = {André Ebert and Sebastian Feld and Martin Werner},
  booktitle = {12. GI/ITG KuVS Fachgespräch Ortsbezogene Anwendungen und Dienste (LBAS 2015)},
  year = {2015},
  owner = {aebert}
  }

• S. Feld, „Scoring of Alternative Routes Using Implicit Building Topologies,“ in Science and Information Conference (SAI 2015), 2015, pp. 329-336.
  [BibTeX] [Abstract]
  

  Currently navigation in indoor scenarios enjoys a highly increasing popularity. Besides that, there are numerous applications that utilize alternatives to a particular path. Think of a navigation system that proposes a mall’s visitor three different routes: the fastest, a route passing restaurants, and a route traversing shops. Thus, the visitor is able to choose a route by personal preference or experience. Further users of alternative routes can be fire fighters, mobile robots, or nonplayer characters in video games. In contrast to navigation in road networks, there are several challenges to solve in indoor scenarios. First, the creation of alternative routes is not much discussed in literature. Second, due to the high degree of freedom there is a large number of alternative routes possible regarding a reference path. Third, there is no proper understanding of how to measure the meaningfulness or quality of an alternative route. This paper is a step towards the evaluation of alternative routes in indoor navigation scenarios and has got two main contributions. First, we propose to use the term congestion probability as a first common understanding to estimate the meaningfulness of alternative routes inside buildings. Most of the indoor use cases are looking for routes that either seek or avoid crowded areas – at least as one of multiple criteria. Additionally, we propose to score alternative routes based on a local and a global perception. The paper’s second contribution is an algorithm that scores a set of alternative routes based on an ordinary floor plan. Thus, it compares a formerly non-valuated set of routes and creates a ranking regarding the congestion probability. Basically, the algorithm is based on the assumption that points on a map, that are frequently located on shortest paths, will also be frequently traversed. Due to the lack of appropriate data sets we discuss the algorithm’s results in detail by means of four different indoor scenarios.

  @inproceedings{feld2015scoring,
  title = {Scoring of Alternative Routes Using Implicit Building Topologies},
  author = {Sebastian Feld},
  booktitle = {Science and Information Conference (SAI 2015)},
  year = {2015},
  organization = {The Science and Information (SAI) Organization Limited},
  pages = {329-336},
  publisher = {IEEE},
  abstract = {Currently navigation in indoor scenarios enjoys a highly increasing popularity. Besides that, there are numerous applications that utilize alternatives to a particular path. Think of a navigation system that proposes a mall's visitor three different routes: the fastest, a route passing restaurants, and a route traversing shops. Thus, the visitor is able to choose a route by personal preference or experience. Further users of alternative routes can be fire fighters, mobile robots, or nonplayer characters in video games. In contrast to navigation in road networks, there are several challenges to solve in indoor scenarios. First, the creation of alternative routes is not much discussed in literature. Second, due to the high degree of freedom there is a large number of alternative routes possible regarding a reference path. Third, there is no proper understanding of how to measure the meaningfulness or quality of an alternative route. This paper is a step towards the evaluation of alternative routes in indoor navigation scenarios and has got two main contributions. First, we propose to use the term congestion probability as a first common understanding to estimate the meaningfulness of alternative routes inside buildings. Most of the indoor use cases are looking for routes that either seek or avoid crowded areas - at least as one of multiple criteria. Additionally, we propose to score alternative routes based on a local and a global perception. The paper's second contribution is an algorithm that scores a set of alternative routes based on an ordinary floor plan. Thus, it compares a formerly non-valuated set of routes and creates a ranking regarding the congestion probability. Basically, the algorithm is based on the assumption that points on a map, that are frequently located on shortest paths, will also be frequently traversed. Due to the lack of appropriate data sets we discuss the algorithm's results in detail by means of four different indoor scenarios.},
  owner = {sfeld}
  }

• S. Feld, M. Werner, M. Schönfeld, and S. Hasler, „Archetypes of Alternative Routes in Buildings,“ in 6th International Conference on Indoor Positioning and Indoor Navigation (IPIN 2015), 2015, pp. 1-10.
  [BibTeX] [Abstract]
  

  Alternative routes have found many applications in navigation scenarios. However, alternative routes have only been introduced recently for the indoor space due to the complexity of these environments. Furthermore, the number of alternative routes in buildings can be quite high. With this paper, we propose to organize sets of alternative routes by employing archetypal analysis on a feature space representation of routes and show results in which a set of hundreds of routes between the same start and end point has been compressed to only a few obviously different archetypal routes. Additionally, the framework allows for comparing routes with archetypes and with each other. This comparison does not reveal spatial similarity alone, but rather a measure of routes‘ similarity representing their inherent semantic character.

  @inproceedings{feld2015archetypes,
  title = {Archetypes of Alternative Routes in Buildings},
  author = {Sebastian Feld and Martin Werner and Mirco Schönfeld and Stefanie Hasler},
  booktitle = {6th International Conference on Indoor Positioning and Indoor Navigation (IPIN 2015)},
  year = {2015},
  pages = {1-10},
  abstract = {Alternative routes have found many applications in navigation scenarios. However, alternative routes have only been introduced recently for the indoor space due to the complexity of these environments. Furthermore, the number of alternative routes in buildings can be quite high. With this paper, we propose to organize sets of alternative routes by employing archetypal analysis on a feature space representation of routes and show results in which a set of hundreds of routes between the same start and end point has been compressed to only a few obviously different archetypal routes. Additionally, the framework allows for comparing routes with archetypes and with each other. This comparison does not reveal spatial similarity alone, but rather a measure of routes' similarity representing their inherent semantic character.},
  owner = {sebastian},
  timestamp = {2015.12.01}
  }

• V. Protschky, S. Feld, and M. Wälischmiller, „Traffic Signal Adaptive Routing,“ in IEEE 18th International Conference on Intelligent Transportation Systems (ITSC 2015), 2015, pp. 450-456.
  [BibTeX] [Abstract]
  

  The knowledge of future Signal Phase and Timing information (SPaT) of traffic lights ahead enables a vast number of driving assistance functions, such as Green Light Optimal Speed Control (GLOSA), Red Light Duration Advisory (RLDA) or Traffic Signal Adaptive routing (TSA routing). The purpose of TSA routing is to reduce the travel time by choosing a route that is possibly longer than the shortest one but has less red lights. Whereas GLOSA and RLDA are quite easy to implement from a scientific point of view, TSA routing presents a certain challenge: first of all, TSA routing necessitates predictions on future signal states on a wider look in the future than GLOSA and RLDA, a possible reason why this field of research still seems rather unexplored. Second, there are still many unresolved issues, such as the inadequacy of graphs for TSA-routing, or proper traffic load estimations. In this paper, we present a fully functioning model for TSA routing on the basis of our forgoing research on the prediction of future signal states and address the question of practical usability by evaluating our model under realistic conditions. We analyze, among other things, the impact of partial knowledge on traffic light’s future signal states and the impact of different traffic loads on TSA routes by means of a test field in Munich, Germany. We describe necessary modifications of the underlying transportation network’s graph structure and shortest path routing algorithm to allow routing under consideration of future signal states of traffic lights. We show that, albeit there are many erratic aspects in traffic and signal states, TSA routing still reaches a significant travel time gain over usual routing in our test field.

  @inproceedings{protschky2015traffic,
  title = {Traffic Signal Adaptive Routing},
  author = {Valentin Protschky and Sebastian Feld and Michael Wälischmiller},
  booktitle = {IEEE 18th International Conference on Intelligent Transportation Systems (ITSC 2015)},
  year = {2015},
  pages = {450-456},
  abstract = {The knowledge of future Signal Phase and Timing information (SPaT) of traffic lights ahead enables a vast number of driving assistance functions, such as Green Light Optimal Speed Control (GLOSA), Red Light Duration Advisory (RLDA) or Traffic Signal Adaptive routing (TSA routing). The purpose of TSA routing is to reduce the travel time by choosing a route that is possibly longer than the shortest one but has less red lights. Whereas GLOSA and RLDA are quite easy to implement from a scientific point of view, TSA routing presents a certain challenge: first of all, TSA routing necessitates predictions on future signal states on a wider look in the future than GLOSA and RLDA, a possible reason why this field of research still seems rather unexplored. Second, there are still many unresolved issues, such as the inadequacy of graphs for TSA-routing, or proper traffic load estimations. In this paper, we present a fully functioning model for TSA routing on the basis of our forgoing research on the prediction of future signal states and address the question of practical usability by evaluating our model under realistic conditions. We analyze, among other things, the impact of partial knowledge on traffic light's future signal states and the impact of different traffic loads on TSA routes by means of a test field in Munich, Germany. We describe necessary modifications of the underlying transportation network's graph structure and shortest path routing algorithm to allow routing under consideration of future signal states of traffic lights. We show that, albeit there are many erratic aspects in traffic and signal states, TSA routing still reaches a significant travel time gain over usual routing in our test field.},
  owner = {vprotschky}
  }

2014

• M. T. Beck, M. Werner, S. Feld, and T. Schimper, „Mobile Edge Computing: A taxonomy,“ in 6h International Conference on Advances in Future Internet (AFIN 2014), 2014, pp. 48-54.
  [BibTeX] [Abstract]
  

  Mobile Edge Computing proposes co-locating computing and storage resources at base stations of cellular networks. It is seen as a promising technique to alleviate utilization of the mobile core and to reduce latency for mobile end users. Due to the fact that Mobile Edge Computing is a novel approach not yet deployed in real-life networks, recent work discusses merely general and non-technical ideas and concepts. This paper introduces a taxonomy for Mobile Edge Computing applications and analyzes chances and limitations from a technical point of view. Application types which profit from edge deployment are identified and discussed. Furthermore, these applications are systematically classified based on technical metrics.

  @inproceedings{mectaxonomy,
  title = {Mobile Edge Computing: A taxonomy},
  author = {Michael Till Beck and Martin Werner and Sebastian Feld and Thomas Schimper},
  booktitle = {6h International Conference on Advances in Future Internet (AFIN 2014)},
  year = {2014},
  pages = {48-54},
  publisher = {IARIA},
  abstract = {Mobile Edge Computing proposes co-locating computing and storage resources at base stations of cellular networks. It is seen as a promising technique to alleviate utilization of the mobile core and to reduce latency for mobile end users. Due to the fact that Mobile Edge Computing is a novel approach not yet deployed in real-life networks, recent work discusses merely general and non-technical ideas and concepts. This paper introduces a taxonomy for Mobile Edge Computing applications and analyzes chances and limitations from a technical point of view. Application types which profit from edge deployment are identified and discussed. Furthermore, these applications are systematically classified based on technical metrics.},
  keywords = {Edge Deployment, Cellular Networks, Classification},
  owner = {mbeck}
  }

• F. Dorfmeister, S. Feld, and C. Linnhoff-Popien, „ALPACA: A Decentralized, Privacy-Centric and Context-Aware Framework for the Dissemination of Context Information,“ International Journal On Advances in Intelligent Systems, vol. 7, iss. 1 and 2, pp. 223-236, 2014.
  [BibTeX] [Abstract]
  

  With the ongoing rise of smartphones as everyday mobile devices and their steadily increasing amount of sensing and communication capabilities, we are on the brink of a subtle, widespread adoption of context-aware computing techniques into our daily lives. Focusing on functionality and performance, the majority of existing architectures for managing context information typically deploy central components for collecting, analyzing and distributing its users‘ up-to-date data. However, preservation of users‘ privacy needs remains a crucial factor for such systems‘ acceptableness. Inspired by existing works on privacy in context-aware applications and the authors‘ beliefs in the necessity to put users back in control, this article adopts a privacy-centric perspective and presents ALPACA: A novel approach for modeling and managing a user’s rich context information in a user-centric and privacy-preserving way fit for a multitude of different usage scenarios. To this end, this article offers a general conceptual mapping of a user’s privacy needs to distinct layers. Based on this conceptualization we introduce a privacy-centric approach for modeling this information. Additionally, we propose a context-aware mechanism for the definition of context-dependent release triggers in order to enable fine-grained control over the disclosure of sensitive information. Finally, we present the components of the proposed system architecture, explain how they interact with each other and discuss how our framework can be integrated into a modern mobile operating system.

  @article{dorfmeister2014alpaca,
  title = {ALPACA: A Decentralized, Privacy-Centric and Context-Aware Framework for the Dissemination of Context Information},
  author = {Florian Dorfmeister and Sebastian Feld and Claudia Linnhoff-Popien},
  journal = {International Journal On Advances in Intelligent Systems},
  year = {2014},
  number = {1 and 2},
  pages = {223-236},
  volume = {7},
  abstract = {With the ongoing rise of smartphones as everyday mobile devices and their steadily increasing amount of sensing and communication capabilities, we are on the brink of a subtle, widespread adoption of context-aware computing techniques into our daily lives. Focusing on functionality and performance, the majority of existing architectures for managing context information typically deploy central components for collecting, analyzing and distributing its users' up-to-date data. However, preservation of users' privacy needs remains a crucial factor for such systems' acceptableness. Inspired by existing works on privacy in context-aware applications and the authors' beliefs in the necessity to put users back in control, this article adopts a privacy-centric perspective and presents ALPACA: A novel approach for modeling and managing a user's rich context information in a user-centric and privacy-preserving way fit for a multitude of different usage scenarios. To this end, this article offers a general conceptual mapping of a user's privacy needs to distinct layers. Based on this conceptualization we introduce a privacy-centric approach for modeling this information. Additionally, we propose a context-aware mechanism for the definition of context-dependent release triggers in order to enable fine-grained control over the disclosure of sensitive information. Finally, we present the components of the proposed system architecture, explain how they interact with each other and discuss how our framework can be integrated into a modern mobile operating system.},
  owner = {fdorfmeister}
  }

• S. Feld, M. Schönfeld, and M. Werner, „Analyzing the Deployment of Bitcoin’s P2P Network under an AS-level Perspective,“ in 5th International Conference on Ambient Systems, Networks and Technologies (ANT 2014) and 4th International Conference on Sustainable Energy Information Technology (SEIT 2014), 2014, pp. 1121-1126.
  [BibTeX] [Abstract] [Download PDF]
  

  Bitcoin has become increasingly important in recent years. The exchange rate raised from \$14 in January 2013 up to \$240 in April 2013 and even \$900 in early 2014. In this paper, we present novel insights about Bitcoin’s peer-to-peer (P2P) network with a special focus on its distribution among distinct autonomous systems. We traversed Bitcoin’s P2P network in a protocol-compliant manner and collected information about the network size, the number of clients, and the network distribution among autonomous systems. Our findings lead to conclusions about the resilience of the Bitcoin ecosystem, the unambiguousness of the blockchain in use, and the propagation and verification of transaction blocks.

  @inproceedings{bitcoin,
  title = {Analyzing the Deployment of Bitcoin's P2P Network under an AS-level Perspective},
  author = {Sebastian Feld and Mirco Schönfeld and Martin Werner},
  booktitle = {5th International Conference on Ambient Systems, Networks and Technologies (ANT 2014) and 4th International Conference on Sustainable Energy Information Technology (SEIT 2014)},
  year = {2014},
  pages = {1121-1126},
  abstract = {Bitcoin has become increasingly important in recent years. The exchange rate raised from \$14 in January 2013 up to \$240 in April 2013 and even \$900 in early 2014. In this paper, we present novel insights about Bitcoin's peer-to-peer (P2P) network with a special focus on its distribution among distinct autonomous systems. We traversed Bitcoin's P2P network in a protocol-compliant manner and collected information about the network size, the number of clients, and the network distribution among autonomous systems. Our findings lead to conclusions about the resilience of the Bitcoin ecosystem, the unambiguousness of the blockchain in use, and the propagation and verification of transaction blocks.},
  file = {pdf?md5=2a5efb534e0d4dc1e12ba9b4157ae4c9&pid=1-s2.0-S187705091400742X-main.pdf:http\://www.sciencedirect.com/science/article/pii/S187705091400742X/pdf?md5=2a5efb534e0d4dc1e12ba9b4157ae4c9&pid=1-s2.0-S187705091400742X-main.pdf:PDF},
  owner = {sfeld},
  url = {http://www.sciencedirect.com/science/article/pii/S187705091400742X}
  }

• S. Feld and M. Werner, „Compression of GPS tracks Using Map Information,“ in 11. GI/ITG KuVS Fachgespräch Ortsbezogene Anwendungen und Dienste (LBAS 2014), 2014, pp. 103-114.
  [BibTeX] [Abstract]
  

  With this paper, we propose a novel semantic compression scheme for GPS trajectories which exploits map knowledge for data reduction. Therefore, the compression is integrated into a simple map matching scheme and shows superior performance with respect to the compression ratio. In contrast to other compression schemes including compressed GPX files, a lot of information about a trajectory can be readily extracted from the given representation and a uniformly sampled representative can be easily calculated for advanced trajectory comparison. We provide a detailed analysis of the approach as well as preliminary results on performance and feasibility of this approach in typical urban mobility scenarios.

  @inproceedings{feld2014compression,
  title = {Compression of GPS tracks Using Map Information},
  author = {Sebastian Feld and Martin Werner},
  booktitle = {11. GI/ITG KuVS Fachgespräch Ortsbezogene Anwendungen und Dienste (LBAS 2014)},
  year = {2014},
  pages = {103-114},
  abstract = {With this paper, we propose a novel semantic compression scheme for GPS trajectories which exploits map knowledge for data reduction. Therefore, the compression is integrated into a simple map matching scheme and shows superior performance with respect to the compression ratio. In contrast to other compression schemes including compressed GPX files, a lot of information about a trajectory can be readily extracted from the given representation and a uniformly sampled representative can be easily calculated for advanced trajectory comparison. We provide a detailed analysis of the approach as well as preliminary results on performance and feasibility of this approach in typical urban mobility scenarios.},
  owner = {sfeld}
  }

• C. Marouane, M. Maier, S. Feld, and M. Werner, „Visual Positioning Systems – An Extension to MoVIPS,“ in 5th International Conference on Indoor Positioning and Indoor Navigation (IPIN 2014), 2014, pp. 95-104.
  [BibTeX] [Abstract]
  

  Due to the increasing popularity of location-based services, the need for reliable and cost-effective indoor positioning methods is rising. As an alternative to radio-based localization methods, in 2011, we introduced MoVIPS (Mobile Visual Indoor Positioning System), which is based on the idea to extract visual feature points from a query image and compare them to those of previously collected geo-referenced images. The general feasibility of positioning by SURF points on a conventional smartphone was already shown in our previous work. However, the system still faced several shortcomings concerning real-world usage such as request times being too high and distance estimation being unreliable because of the employed estimation method not being rotation invariant. In this paper, three extensions are presented that improve the practical applicability of MoVIPS. To speed up request times, both a dead reckoning approach (based on step counting using the accelerometer) and an orientation estimation (based on the smartphone’s compass) are introduced to filter relevant images from the database and thus to reduce the amount of images to compare the query image to. Furthermore, the vectors of the SURF points are quantized. For this purpose, clusters are calculated from all SURF points from the database. As a result, each image can be represented by a histogram of cluster frequencies, which can be compared with each other a lot more efficiently. The third extension is an improvement of the distance estimation method, which uses the matched feature points of an image to perform a perspective transformation and to determine the actual position with the aid of the transformation matrix. Employing the first extension, request times are reduced by 84\% percent. The quantization of the SURF points reduces the search time by a factor of 1000. Finally, the distance estimation is now rotation invariant and enables a better position correction.

  @inproceedings{marouane2014visual,
  title = {Visual Positioning Systems - An Extension to MoVIPS},
  author = {Chadly Marouane and Marco Maier and Sebastian Feld and Martin Werner},
  booktitle = {5th International Conference on Indoor Positioning and Indoor Navigation (IPIN 2014)},
  year = {2014},
  pages = {95-104},
  abstract = {Due to the increasing popularity of location-based services, the need for reliable and cost-effective indoor positioning methods is rising. As an alternative to radio-based localization methods, in 2011, we introduced MoVIPS (Mobile Visual Indoor Positioning System), which is based on the idea to extract visual feature points from a query image and compare them to those of previously collected geo-referenced images. The general feasibility of positioning by SURF points on a conventional smartphone was already shown in our previous work. However, the system still faced several shortcomings concerning real-world usage such as request times being too high and distance estimation being unreliable because of the employed estimation method not being rotation invariant. In this paper, three extensions are presented that improve the practical applicability of MoVIPS. To speed up request times, both a dead reckoning approach (based on step counting using the accelerometer) and an orientation estimation (based on the smartphone's compass) are introduced to filter relevant images from the database and thus to reduce the amount of images to compare the query image to. Furthermore, the vectors of the SURF points are quantized. For this purpose, clusters are calculated from all SURF points from the database. As a result, each image can be represented by a histogram of cluster frequencies, which can be compared with each other a lot more efficiently. The third extension is an improvement of the distance estimation method, which uses the matched feature points of an image to perform a perspective transformation and to determine the actual position with the aid of the transformation matrix. Employing the first extension, request times are reduced by 84\% percent. The quantization of the SURF points reduces the search time by a factor of 1000. Finally, the distance estimation is now rotation invariant and enables a better position correction.},
  owner = {cmarouane}
  }

• M. Werner and S. Feld, „Homotopy and Alternative Routes in Indoor Navigation Scenarios,“ in 5th International Conference on Indoor Positioning and Indoor Navigation (IPIN 2014), 2014, pp. 230-238.
  [BibTeX] [Abstract]
  

  There are lots of innovative use cases possible that build on a shortest route between two locations together with a set of alternatives that are highly different yet short. Imagine, for example, a complicated building like an airport, where passengers can consult a computer terminal to get navigation advices to a desired goal. By scanning the boarding card the calculation of alternatives can be made context-sensitive. Based on gender, amount of time, or shopping preferences, for example, the terminal can display different routes regarding floors traversed, or shops and restaurants passed. Furthermore, the building operator can control the presentation of alternatives in order to influence visitor flows in real time. Therefore, we propose to use the topological concept of homotopy in order to decide if two routes should be considered equivalent or alternative. Basically, the homotopy relation identifies equivalence classes. We propose that a representative of an equivalence class is an alternative regarding another equivalence class. We concatenate the two routes in question and thus, create a polygon. If there is an obstacle inside, the routes are non-homotopic and we consider them as proper alternatives. For this situation, we propose two fundamentally different approaches that are able to find alternative routes with respect to homotopy. The input is a building plan in form of an occupancy grid. Bitmaps allow for fast calculation of the homotopy relation and can be generated from almost any type of environmental model. The first approach aims for enumerating routes that have to visit a special supporting point. This concatenation of two shortest paths leads to alternatives very fast. The second approach is orthogonal to that in the sense that it generates alternatives roughly ordered by their length. Finally, we evaluate and discuss the approaches‘ feasibility based on different metrics in several scenarios.­­­­­­­­

  @inproceedings{werner2014homotopy,
  title = {Homotopy and Alternative Routes in Indoor Navigation Scenarios},
  author = {Martin Werner and Sebastian Feld},
  booktitle = {5th International Conference on Indoor Positioning and Indoor Navigation (IPIN 2014)},
  year = {2014},
  pages = {230-238},
  abstract = {There are lots of innovative use cases possible that build on a shortest route between two locations together with a set of alternatives that are highly different yet short. Imagine, for example, a complicated building like an airport, where passengers can consult a computer terminal to get navigation advices to a desired goal. By scanning the boarding card the calculation of alternatives can be made context-sensitive. Based on gender, amount of time, or shopping preferences, for example, the terminal can display different routes regarding floors traversed, or shops and restaurants passed. Furthermore, the building operator can control the presentation of alternatives in order to influence visitor flows in real time. Therefore, we propose to use the topological concept of homotopy in order to decide if two routes should be considered equivalent or alternative. Basically, the homotopy relation identifies equivalence classes. We propose that a representative of an equivalence class is an alternative regarding another equivalence class. We concatenate the two routes in question and thus, create a polygon. If there is an obstacle inside, the routes are non-homotopic and we consider them as proper alternatives. For this situation, we propose two fundamentally different approaches that are able to find alternative routes with respect to homotopy. The input is a building plan in form of an occupancy grid. Bitmaps allow for fast calculation of the homotopy relation and can be generated from almost any type of environmental model. The first approach aims for enumerating routes that have to visit a special supporting point. This concatenation of two shortest paths leads to alternatives very fast. The second approach is orthogonal to that in the sense that it generates alternatives roughly ordered by their length. Finally, we evaluate and discuss the approaches' feasibility based on different metrics in several scenarios.­­­­­­­­},
  owner = {mwerner}
  }

• K. Wiesner, S. Feld, F. Dorfmeister, and C. Linnhoff-Popien, „Right to Silence: Establishing Map-based Silent Zones for Participatory Sensing,“ in IEEE 9th International Conference on Intelligent Sensors, Sensor Networks and Information Processing (IEEE ISSNIP 2014), 2014, pp. 339-344.
  [BibTeX] [Abstract]
  

  Participatory sensing tries to create cost-effective, large-scale sensing systems by leveraging sensors embedded in mobile devices. One major challenge in these systems is to protect the users‘ privacy, since users will not contribute data if their privacy is jeopardized. Especially location data needs to be protected if it is likely to reveal information about the users‘ identities. A common solution is the blinding out approach that creates so-called ban zones in which location data is not published. Thereby, a user’s important places, e.g., her home or workplace, can be concealed. However, ban zones of a fixed size are not able to guarantee any particular level of privacy. For instance, a ban zone that is large enough to conceal a user’s home in a large city might be too small in a less populated area. For this reason, we propose an approach for dynamic map-based blinding out: The boundaries of our privacy zones, called Silent Zones, are determined in such way that at least k buildings are located within this zone. Thus, our approach adapts to the habitat density and we can guarantee k-anonymity in terms of surrounding buildings. In this paper, we present two new algorithms for creating Silent Zones and evaluate their performance. Our results show that especially in worst case scenarios, i.e., in sparsely populated areas, our approach outperforms standard ban zones and guarantees the specified privacy level.

  @inproceedings{silentzones,
  title = {Right to Silence: Establishing Map-based Silent Zones for Participatory Sensing},
  author = {Kevin Wiesner and Sebastian Feld and Florian Dorfmeister and Claudia Linnhoff-Popien},
  booktitle = {IEEE 9th International Conference on Intelligent Sensors, Sensor Networks and Information Processing (IEEE ISSNIP 2014)},
  year = {2014},
  pages = {339-344},
  abstract = {Participatory sensing tries to create cost-effective, large-scale sensing systems by leveraging sensors embedded in mobile devices. One major challenge in these systems is to protect the users' privacy, since users will not contribute data if their privacy is jeopardized. Especially location data needs to be protected if it is likely to reveal information about the users' identities. A common solution is the blinding out approach that creates so-called ban zones in which location data is not published. Thereby, a user's important places, e.g., her home or workplace, can be concealed. However, ban zones of a fixed size are not able to guarantee any particular level of privacy. For instance, a ban zone that is large enough to conceal a user's home in a large city might be too small in a less populated area. For this reason, we propose an approach for dynamic map-based blinding out: The boundaries of our privacy zones, called Silent Zones, are determined in such way that at least k buildings are located within this zone. Thus, our approach adapts to the habitat density and we can guarantee k-anonymity in terms of surrounding buildings. In this paper, we present two new algorithms for creating Silent Zones and evaluate their performance. Our results show that especially in worst case scenarios, i.e., in sparsely populated areas, our approach outperforms standard ban zones and guarantees the specified privacy level.},
  owner = {kwiesner}
  }

2013

• F. Dorfmeister, S. Feld, C. Linnhoff-Popien, and S. A. W. Verclas, „Privacy-Centric Modeling and Management of Context Information,“ in 6th International Conference on Advances in Human oriented and Personalized Mechanisms, Technologies, and Services (CENTRIC 2013), 2013, pp. 92-97.
  [BibTeX] [Abstract]
  

  Context-aware computing has been an intensively researched topic for years already. Consequently, there exists a plethora of usage scenarios for context-aware applications as well as several approaches for the modeling and management of a user’s context information, many of which focus on the efficient and scalable distribution of the latter. With the ongoing rise of smartphones as everyday mobile devices and their steadily increasing amount of sensing and communication capabilities, we finally find ourselves at the edge towards a widespread usage of these techniques. However, apart from technical issues such as how to reliably determine a user’s current context, privacy still remains a crucial factor for these systems’ acceptance rate. Therefore, inspired by earlier works on privacy in context-aware computing and the authors’ beliefs in the necessity to put users in control, this paper presents a novel approach for modeling and managing a mobile user’s context information in a user-centric and privacy-preserving way. To this end, this work’s contribution is twofold: First, based on widely recognized requirements for privacy in context-aware applications, we propose a privacy-centric context model which allows for an intuitive and context-dependent definition of a user’s privacy preferences, directly integrating privacy aspects into the context model itself. Second, we present a generic and flexible architecture for the management and distribution of context information in a privacy-preserving way fit for a multitude of different usage scenarios.

  @inproceedings{dorfmeister2013privacy,
  title = {Privacy-Centric Modeling and Management of Context Information},
  author = {Florian Dorfmeister and Sebastian Feld and Claudia Linnhoff-Popien and Stephan A. W. Verclas},
  booktitle = {6th International Conference on Advances in Human oriented and Personalized Mechanisms, Technologies, and Services (CENTRIC 2013)},
  year = {2013},
  pages = {92-97},
  abstract = {Context-aware computing has been an intensively researched topic for years already. Consequently, there exists a plethora of usage scenarios for context-aware applications as well as several approaches for the modeling and management of a user's context information, many of which focus on the efficient and scalable distribution of the latter. With the ongoing rise of smartphones as everyday mobile devices and their steadily increasing amount of sensing and communication capabilities, we finally find ourselves at the edge towards a widespread usage of these techniques. However, apart from technical issues such as how to reliably determine a user’s current context, privacy still remains a crucial factor for these systems’ acceptance rate. Therefore, inspired by earlier works on privacy in context-aware computing and the authors’ beliefs in the necessity to put users in control, this paper presents a novel approach for modeling and managing a mobile user’s context information in a user-centric and privacy-preserving way. To this end, this work’s contribution is twofold: First, based on widely recognized requirements for privacy in context-aware applications, we propose a privacy-centric context model which allows for an intuitive and context-dependent definition of a user’s privacy preferences, directly integrating privacy aspects into the context model itself. Second, we present a generic and flexible architecture for the management and distribution of context information in a privacy-preserving way fit for a multitude of different usage scenarios.},
  owner = {fdorfmeister}
  }

• S. Feld and M. Werner, „Efficient Path Planning Involving Equivalent Places,“ in 10. GI/ITG KuVS Fachgespräch Ortsbezogene Anwendungen und Dienste (LBAS 2013), 2013, pp. 13-22.
  [BibTeX] [Abstract]
  

  This paper investigates a complication of the classical Traveling Salesman Problem, which arises due to multiple points of interest with functional equivalence. While the classical Traveling Salesman Problem tries to find a shortest tour visiting each point in a set exactly once, we consider the challenge of finding the shortest tour visiting each point of a given set exactly once and exactly one additional point out of a different set of equivalent places. The insertion of a gas station to a traveling salesman problem provides an example. With this paper, we investigate and analyze different algorithms to solve this complex problem by reducing it to the solution of a set of classic Traveling Salesman Problems. Furthermore, we provide an efficient tradeoff between the size of the set of traditional problems still to be solved and the expected error of the algorithm.

  @inproceedings{equivalentplan,
  title = {Efficient Path Planning Involving Equivalent Places},
  author = {Sebastian Feld and Martin Werner},
  booktitle = {10. GI/ITG KuVS Fachgespräch Ortsbezogene Anwendungen und Dienste (LBAS 2013)},
  year = {2013},
  pages = {13-22},
  publisher = {Logos Verlag Berlin},
  abstract = {This paper investigates a complication of the classical Traveling Salesman Problem, which arises due to multiple points of interest with functional equivalence. While the classical Traveling Salesman Problem tries to find a shortest tour visiting each point in a set exactly once, we consider the challenge of finding the shortest tour visiting each point of a given set exactly once and exactly one additional point out of a different set of equivalent places. The insertion of a gas station to a traveling salesman problem provides an example. With this paper, we investigate and analyze different algorithms to solve this complex problem by reducing it to the solution of a set of classic Traveling Salesman Problems. Furthermore, we provide an efficient tradeoff between the size of the set of traditional problems still to be solved and the expected error of the algorithm.},
  owner = {sfeld}
  }

• K. Wiesner and S. Feld, „Energy-efficient Tasking in Participatory Sensing Systems,“ in 10. GI/ITG KuVS Fachgespräch Ortsbezogene Anwendungen und Dienste (LBAS 2013), 2013, pp. 127-136.
  [BibTeX] [Abstract]
  

  By leveraging sensors embedded in mobile devices, participatory sensing tries to create large-scale sensing systems. One major challenge in these participatory sensing networks is the problem of distributing sensing tasks in an energy-efficient manner. A large portion of energy is typically consumed for the exchange of tasks between the tasking server and the mobile devices, as well as for the position monitoring needed to detect whether a user is situated within the tasking area. In this paper, we mainly focus on reducing energy for receiving and monitoring tasks on the client side. We propose an energy-efficient task distribution and monitoring concept for participatory sensing systems and evaluate it by means of simulation.

  @inproceedings{taskingpsn,
  title = {Energy-efficient Tasking in Participatory Sensing Systems},
  author = {Kevin Wiesner and Sebastian Feld},
  booktitle = {10. GI/ITG KuVS Fachgespräch Ortsbezogene Anwendungen und Dienste (LBAS 2013)},
  year = {2013},
  pages = {127-136},
  publisher = {Logos Verlag Berlin},
  abstract = {By leveraging sensors embedded in mobile devices, participatory sensing tries to create large-scale sensing systems. One major challenge in these participatory sensing networks is the problem of distributing sensing tasks in an energy-efficient manner. A large portion of energy is typically consumed for the exchange of tasks between the tasking server and the mobile devices, as well as for the position monitoring needed to detect whether a user is situated within the tasking area. In this paper, we mainly focus on reducing energy for receiving and monitoring tasks on the client side. We propose an energy-efficient task distribution and monitoring concept for participatory sensing systems and evaluate it by means of simulation.},
  owner = {kwiesner}
  }

2012

• S. Feld, N. Pohlmann, M. Sparenberg, and B. Wichmann, „Analyzing G-20’s key autonomous systems and their intermeshing using AS-Analyzer,“ in Information Security Solutions Europe 2012 Conference (ISSE 2012), 2012, p. 228–242.
  [BibTeX]

  @inproceedings{feld2012analyzing,
  title = {Analyzing G-20’s key autonomous systems and their intermeshing using AS-Analyzer},
  author = {Feld, Sebastian and Pohlmann, Norbert and Sparenberg, Michael and Wichmann, Bastian},
  booktitle = {Information Security Solutions Europe 2012 Conference (ISSE 2012)},
  year = {2012},
  organization = {Springer Vieweg},
  pages = {228--242},
  owner = {sfeld}
  }

2011

• S. Feld, T. Perrei, N. Pohlmann, and M. Schupp, „Ein Internet-Kennzahlensystem für Deutschland: Anforderungen und technische Maßnahmen,“ in DA-CH Security 2011, 2011, p. 544–554.
  [BibTeX]

  @inproceedings{feld2011internet,
  title = {Ein Internet-Kennzahlensystem f{\"u}r Deutschland: Anforderungen und technische Ma{\ss}nahmen},
  author = {Feld, Sebastian and Perrei, Tim and Pohlmann, Norbert and Schupp, Matthias},
  booktitle = {DA-CH Security 2011},
  year = {2011},
  organization = {IT-Quartier Oldenburg},
  pages = {544--554},
  owner = {sfeld}
  }

• S. Feld, T. Perrei, N. Pohlmann, and M. Schupp, „Objectives and Added Value of an Internet Key Figure System for Germany,“ in Information Security Solutions Europe 2011 Conference (ISSE 2011), 2011, p. 341–351.
  [BibTeX]

  @inproceedings{feld2011objectives,
  title = {Objectives and Added Value of an Internet Key Figure System for Germany},
  author = {Feld, Sebastian and Perrei, Tim and Pohlmann, Norbert and Schupp, Matthias},
  booktitle = {Information Security Solutions Europe 2011 Conference (ISSE 2011)},
  year = {2011},
  organization = {Vieweg+Teubner},
  pages = {341--351},
  owner = {sfeld}
  }

• S. Feld and N. Pohlmann, „Security Analysis of OpenID, followed by a Reference Implementation of an nPA-based OpenID Provider,“ in Information Security Solutions Europe 2010 Conference (ISSE 2010), 2011, p. 13–25.
  [BibTeX]

  @inproceedings{feld2011security,
  title = {Security Analysis of OpenID, followed by a Reference Implementation of an nPA-based OpenID Provider},
  author = {Feld, Sebastian and Pohlmann, Norbert},
  booktitle = {Information Security Solutions Europe 2010 Conference (ISSE 2010)},
  year = {2011},
  organization = {Vieweg+Teubner},
  pages = {13--25},
  owner = {sfeld}
  }

2010

• S. Feld and N. Pohlmann, „Ein OpenID-Provider mit Proxy-Funktionalitat für den nPA,“ in D-A-CH Security 2010, 2010, p. 31–44.
  [BibTeX]

  @inproceedings{feld2010openid,
  title = {Ein OpenID-Provider mit Proxy-Funktionalitat f{\"u}r den nPA},
  author = {Feld, Sebastian and Pohlmann, Norbert},
  booktitle = {D-A-CH Security 2010},
  year = {2010},
  organization = {IT-Quartier Oldenburg},
  pages = {31--44},
  owner = {sfeld}
  }

2009

• S. Feld, N. Pohlmann, and S. Spooren, „Gefahren und Risiken bei Web 2.0,“ HMD Praxis der Wirtschaftsinformatik, vol. 46, iss. 3, p. 104–112, 2009.
  [BibTeX]

  @article{feld2009gefahren,
  title = {Gefahren und Risiken bei Web 2.0},
  author = {Feld, Sebastian and Pohlmann, Norbert and Spooren, Sebastian},
  journal = {HMD Praxis der Wirtschaftsinformatik},
  year = {2009},
  number = {3},
  pages = {104--112},
  volume = {46},
  owner = {sfeld},
  publisher = {Gabler Verlag}
  }